I've been unable to upgrade from NiFi 1.8 due to a strange behavior of the current (as of this 1.11.1) version.
It keeps opening files and not closing them!!
We've set our servers max file limits to 50,000. That helps a bit since NiFi them will crash after 3 to 4 days instead of 3 to 4 hours.
Can someone help me. I don't want to be locked in version 1.8.
I'm assuming that you are the same person who opened the JIRA ticket NIFI-7114. While we welcome your question, and you may get an answer from someone in the community, you might want to wait until an Apache committer responds to your JIRA ticket. There might be a simple solution.